I have main bearing insert in my 91 lt250r. I done complete rebuild of my bottom end all oem sgp parts.. I have a build thread in the section members build. But my crank wobbled super bad back and fourth. It as either new cases or inserts. So I went new inserts. I had another set of 87 cases laying around as spares.  1 owner cases, bike was stock it whole life. Well the bearing inserts were bad in them to. So that why I went with inserts I didnt want to take a chance buy a used set with same problems. But inesrts will cost around 160 to 180$ per bearing pocket.